Nondeflection support for web carrying roll



BQSKAUGEN March 4, 1969 NONDEFLECTION SUPPORT FOR WEB CARRYING ROLLFiled Aug. 15, 1966 I AVEA'TOR. Bar-y :Siaaysw A T TORN E YS UnitedStates Patent 3,430,319 NONDEFLECTION SUPPORT FOR WEB CARRYING ROLL BorgSkaugen, Beloit, Wis., assignor to Beloit Corporation, Beloit, Wis., acorporation of Wisconsin Filed Aug. 15, 1966, Ser. No. 572,425

US. Cl. 29-116 Claims Int. Cl. 1321b 13/00 ABSTRACT OF THE DISCLOSURE Arotary roll shell supported interiorly along its length atcircumferentially spaced locations such as by a sliding flexible shoesupported by piston in a cylinder carried on a stationary axiallyextending shaft.

The present invention relates to improvements in web carrying rolls andmore particularly to supports for rolls of the type used for carryingFourdrinier wires in paper making machines.

In paper making machines having traveling wire for receiving the pulpsuspension and dewatering the pulp the wires are carried on rolls whichshould have a minimum of deflection. Deflection of the rolls causesbending of the wire and resultant wear and breakage. This isparticularly a problem in paper machines of increasing wider widths, andthe breast roll, couch roll and other rolls must be made of increasingstrength to avoid deflection. While the features of the presentinvention are particularly applicable and useful in wire supporting[[0118 in a paper machine, they are also applicable and useful in otherroll installations where a roll must carry and support a traveling webelement and in the specification and claims the term web is usedgenerically to refer to a web member which is carried by a roll.

An object of the present invention is to provide an improved rollassembly structure which is capable of carrying heavy loads withoutbending and is particularly useful in rolls used to carry a travelingFourdrinier wire.

Another important object of the invention is to provide a roll structureparticularly adapted for use in carrying a wire in a Fourdrinier machinewherein a hollow roll shell is employed supported from within the shellthe support capable of handling different loads on the roll.

A still further object of the invention is to provide an improved rollassembly wherein a hollow roll shell is used supported from within sothat the loads on the roll shell are transmitted to a stationary shaftmember within the roll shell and the support is capable of accommodatingloads of forces on the roll shell which are changeable either indirection or size or both.

A still further object of the invention is to provide an improvedsupport structure for a rotatable roll shell capable of carrying atraveling web wherein the support structure can carry heavy loads andhas a long wearing life so as to be able to operate continuously overyears of operation and not require shutdown for adjustment or repair.

Other objects, advantages and features will become more apparent withthe teaching of the principles of the invention in connection with thedisclosure of the preferred embodiments of the invention in thespecification and drawings in which:

FIGURE 1 is a vertical sectional view shown somewhat schemtaically,illustrating a roll assembly embodying the principles of the presentinvention;

FIGURE 2 is an elevational view of the roll of FIG- URE 1 with portionsbroken away; and

FIGURE 3 is a force diagram illustrating forces on the 3,430,319Patented Mar. 4, 1969 roll from weight of the roll and tensions on theweb wrapping the roll.

In the drawings:

FIGURES 1 and 2 illustrate a roll shell 10 supporting a traveling web orwire W which is under tension. The roll shell 10 may be employed as thereturn roll for carrying the wire in a Fourdrinier machine or theprinciples may be employed in the breast roll, couch roll or tensionrolls in the Fourdrinier machine and the principles may also be employedin felt carrying rolls or other rolls in a paper machine, or othermachine wherein traveling webs or belts are carried.

Instead of making a roll which is sufliciently strong to support a wireW under tension without excessive deflection, or instead of providingbackup supports exterior of the roll, the roll 10 is hollow andrelatively light weight and supported from the inside to preventbending. How ever it will be appreciated by those versed in the art, ina Fourdrinier wire the tension is regulated and changed with differentoperating conditions so that the forces on all of the wire carryingrolls are changed. The total forces on each of the rolls are thecombined forces of the weight of the roll and the weight of the wireplus the force of the wire tension as it wraps the roll. Another factorwhich may be encountered in some installations is the change of angle ofwrap of the wire on the roll. For example in a roll adjacent a wiretensioning roll, the total angle of wrap will vary with the length ofthe wire and the stretch of the wire as the tension changes. Althoughthe change in tension forces in some instances may be small, the presentinvention contemplates providing a support for the interior of the rollshell which will act along a line which is at the exact angle of theresultant force line due to the tension of the wire.

The present invention also contemplates applying a support force withinthe roll shell or supporting the weight of the shell and the weight ofthe wire carried thereby. In some instances depending upon the locationof the roll, the weight of the wire may be taken as negligible so thatthe internal support basically functions to support the weight of theroll shell.

As shown in FIGURE 1, a first support means 12 is provided for carryingthe weight of the roll shell (and the weight of the wire carriedthereby). A second support means 21 is provided for applying a forcewithin the roll shell to support the force of the tension of the wire W.

The support means 12 and 21 transfer the force of the roll shell 10 to astationary center shaft 11 which is supported at its ends but candeflect within the roll shell.

In a preferred form the support means 12 for supporting the weight ofthe roll shell 10 includes an elongate casting 14 coextensive with theroll shell and having an elongate axially extending chamber 15 thereinwith a piston 16 mounted within the chamber.

A sliding shoe 17 is supported on the piston 16 such as by a cylindricalpin 18 extending along axially between the piston and shoe. Arcuaterecesses are formed on the underside of the shoe and on the upper sideof the piston for seating of the pin 18.

The outer surface of the shoe is circumferentially arenate at the radiusof the inner surface of the roll shell and has its leading or nose endrelieved at 19 so as to gather a lubricating film of oil between theshoe and the shell. To insure that oil will be available within theinner surface of the shell an oil depositing spray 20 is provided alongwithin the shell head of the shoe 17.

Actually while the shoe may be considered as supportingly engaging theinside of the roll shell, a film of oil forms between the shoe and innersurface of the shell so that the shell is hydraulically supported by adynamic film of oil. This film of oil will have a non-uniform pressurecurve across the surface of the shoe in a circumferential direction withthe oil film pressure increasing from the nose 19 to a point of maximumpressure ahead of the trailing edge of the shoe and from the point ofmaximum pressure the pressure drops oflF. The support pin 18 ipreferably positioned so that it will be at the effective force centerof the dynamic oil film between the shoe and the inner surface of theshell (or in other words at the center of gravity of the oil pressurecurve.)

The casting 14 is adjustable circumferentially on the stationary shaft11 and is positioned substantially vertical so it supports the weight ofthe roll shell and the effective force line of the shoe 17 acting on theshell through the rotational center of the roll shell.

The second support means 21 includes a casting 21a which is mounted onthe shaft 11 and is circumferentially adjustable thereon such as byhaving a split collar arrangement with flanges such as shown at 21bwhich have bolts or other securing means to securely clamp the casting21a in its predetermined circumferentially located position.

The casting 21a has an axially extending chamber 23 with a piston 22mounted therein supporting a sliding shoe 24. An axially extending pin25 seats in recesses in the shoe 24 and piston 22.

The shoe has an arcuate outer surface of the inner circumference of theroll shell, and a lead edge is relieved at 26 to form a supporting filmof oil between the outer surface of the shoe and the inner surface ofthe roll shell 10. To insure that oil is present for forming the film aspray 27 is mounted within the roll shell ahead of the shoe 24. Thesprays 20 and 27 for forming the lubricating film are supplied with aoil supply line shown at L in FIG- URE 2.

Hydraulic fluid under pressure is directed into the spaces 15a and 22abeneath the pistons 16 and 22 respectively through lines P-1 and P2.Suitable lines and connections are provided so that pressurized oil canbe directed beneath the pistons and so that the lines will maintainconnection with rotational adjustment of the castings 14 and 21arelative to the shaft 11.

As shown in FIGURE 2, the central shaft 11 is supported at its end witha support 28 shown at one end and the support at the other end notshown. The roll shell is provided with reduced diameter ends a andcentering bearings 29 are provided between the ends 10a and the shaft11.

Suitable connections are provided for the oil lines to the interior ofthe roll shell through the shaft. Lubricating oil is supplied throughthe line L, and a return line R may be provided so that oil can becirculated to maintain a controlled temperature if desired, and to carryaway any oil which may leak past the pistons 16 and 22.

Operation of the structure is contemplated in the manner shown in FIGURE1 wherein one support shoe 17 supports the weight of the roll shell andanother support shoe 24 supports the force caused by the tension of thewire W. Another form of operation is contemplated wherein the shoe 17and its supporting members are omitted and only one support shoe 24 isemployed. In this form of operation the shoe 24 is positioned along theresultant force line which equals the total of the force of the weightof the roll shell and the force of wire tension. These two forms ofoperation may be illustrated in connection with FIGURE 3.

In FIGURE 3 the force due to the weight of the roll is shown at Fw. Thiswill remain constant in any given machine operation and that when thisis determined the pressure of the oil delivered through line P-1 beneaththe piston 16 can be determined and maintained constant. The shoe 17will engage the inside of the roll shell at point 30 which intersectsthe inner surface of the roll shell at a vertical line drawn through theroll center.

The resultant force line due to the tension of the wire W will bedetermined after the angle of wrap of the wire is determined. The forcelines due to tension will act along lines W1 and W2. These will besubstantially equal if the roll 10 is idling but will not be equal ifthe roll is a driving roll and the roll is driven in rotation. FIGURE 3shows the tensions to be equal and at a low tension the tensions causedbythe onrunning and offrunning wire are t-1 with the resultant totalforce being Ft-l. The shoe 24 is adjusted in position so that it engagesthe inner surface of the roll shell 10 at location 31 which is theintersection of the force line Ft-l and the roll shell.

The hydraulic pressure directed to the space beneath the piston 22through line P-2 is controlled so that it applies a force to the shoeFt-l. If the tension increases such as shown by the vector t2, the forceis increased to equal Ft2. Similarly if the tension increases to equalthe vector t-3 then the force is increased to Ft-3.

If the weight supporting shoe 17 is eliminated and a single support shoeis employed, then the force vector which is the result of the force ofthe weight Fw and the force of the tension Ft-l must be drawn, as shownat Fr-l. The oil pressure in the chamber 22a is then adjusted so that aforce is applied to the inside of the shell equal this force Fr-1. Theposition of the shoe 24 is circumferentially adjusted to be located atpoint 32. This point is determined by drawing a line 33 through thecenter of the roll shell parallel to the force resultant line Fr-l.

Similar adjustments in force and position of the shoe 24 must be madefor resultant lines Fr2 for a change in tension to t-2. Similarly for achange in tension to t3 a force resultant Fr3 is drawn and a hydraulicpressure chosen accordingly, and the circumferential location of theshoe 24 adjusted accordingly.

Thus it will be seen that I have provided a roll assembly which iscapable of maintaining a supporting .roll for a traveling web axiallystraight during changes in tension of the web or during changes in angleof wrap of the web. The forces on the roll shell due to its weight anddue to web wrap are'both accommodated and the structure is easilyadjusted to the circumstances of different locations in a machine ordilferent operating conditions.

The drawings and specification present a detailed disclosure of thepreferred embodiments of the invention, and it is to be understood thatthe invention is not limited to the specific forms disclosed, but coversall modifications, changes and alternative constructions and methodsfalling within the scope of the principles taught by the invention.

I claim as my invention:

1. A roll assembly for carrying a traveling web comprising,

a rotatable roll shell for supporting an endless web wrapping the shell,

first and second circumferentially spaced roll shell support means eachsupportingly engaging the inner surface of the roll shell and applying asupporting force adequate for supporting the combined forces of weightof the shell and web and the tension of the web,

and said first support means be in a position to exert a radial force onthe shell equal and opposite to said weight force,

and said second support means he in a position to exert a radial forceon the shell equal and opposite to the tension force of the web.

2. A roll assembly for carrying a traveling web in accordance with claim1 wherein said second support means is circumferentially adjustable toaccommodate change of angle of the web relative to the roll shell.

3. A roll assembly for carrying a traveling Web in accordance with claim1 wherein said second support means is provided with a controllablyvariable pressure means for applying a predetermined radial force on theshell at the location of said second support means.

4. A roll assembly for carrying a traveling web in accordance with claim1 wherein each of the support means includes a sliding shoesubstantially co-extensive with the roll shell,

lubricating means for forming a film of lubricant between the shoes andthe shell, and

a piston and a chamber for each of the shoes extending supportinglybeneath the shoe and the chamber having means for providing it with afluid at a controllably variable pressure.

5. A roll assembly for carrying a traveling web in accordance with claim1 wherein said support means include a stationary supporting shaftextending axially through the roll shell and fluid force transmittingmeans between the shaft and shell for supporting the shell andtransmitting the forces therefrom to the shaft uniformly along thelength of the roll shell.

References Cited UNITED STATES PATENTS 1 1/ 1941 Makarius W 291 1610/1958 Caspari et a1.

10/1963 Westbrook 100-155 1/1964 Justus 100170 5/1964 Kusters et al100170 8/ 1964 Kankaanpaa.

2/1965 Beachler 162-348 FOREIGN PATENTS 4/ 1962 Great Britain.

U.S. Cl. X.R.

